Server Advice

[nifita]

I'd appreciate some advice on our servers here. Please bear with me, I'm new to IT Mgmt.
Right now we have three servers, one is basically file storage, but also runs ArcServe for tape backups (in a Sony Tape Library drive) and our AutoCAD license manager and Sema4 software. Our second server has Exchange, FTP, etc. and runs ISA for a software firewall. Our final server is simply the print server. The first two servers are also both Domain Controllers.
We are at a point where we need more space for file storage, so I'm looking to replace our first server. I've been looking at the Dell PowerEdge 2650 with all 5 bays filled with 146GB hard drives on a RAID 5 array, which will give me application space for the few programs and enough storage space to last a while. Then, I figured we could extend the array when needed with a Dell PowerVault 220S and never run out of space...at least not for some time.
When I spoke to Dell, they were also pushing a smaller server, such as the PowerEdge 1750 and using something like the PowerVault 770N for all the data in one place...which is more expensive right out, but they claimed it to be more expandable and better to have applications separate from file storage in the long run.

My questions:
What are the benefits of doing Dell's suggestion? Is it worth that extra expense up front?
What's the advantage of having dual domain controllers like we do now?
Could I just move the applications from the first server to the second one (that's running Exchange) and just buy a PowerVault 770N for data storage?
Or is my first possibility (PowerEdge 2650 w/ expandability to PowerVault 220S) a good way to do it?

All suggestions welcome! Thank you!

 

[NickFerrar]

Dell's solution is a bit neater in that you'd probably just have a RAID1 system disk in the chassis (the 1750 is a 1U server) and then all the data disks in a separate chassis.

The way you suggest would work fine to but gives a bit less control over how you do your RAIDing.

Do you really need that much data capacity - that's over half a terabyte in a 2650.

Where I work we've agreed a 'rule' that we wouldn't store more than 100GB of data on a single server as restore times get painful beyond that. So we buy servers generally with 4 x 36GB drives and buy a new server when we get near 100GB (you want to leave about 15% free disk space for the MFT on NTFS volumes).

I'd also question doing firewalling on the Exchange server - you really should have a separate dedicated box for firewalling (on which you can tightly lockdown security).
In fact I'd avoid doing anything apart from running Exchange on that server (and AV to go with it).

You certainly want 2 DC's to provide some fault tolerance.

 

[nifita]

Thank you for your input, Nick. Unfortunately, we do need the space, as we work with some large files, all part of active projects that we need to keep available on the server. Buying a new server every time we need 100GB more space would be cost-prohibitive. We keep about 200GB on there right now and have had no troubles with backing up the data. I know a complete restore would take awhile, but wouldn't it take the same amount of time on separate servers, as it would on one? If time was an issue, I wouldn't have to restore all project files at once, just the most critical, and people could still use them while I restored more.
For firewall, we do have a router as a hardware firewall, as well. What conflicts can arise from running ISA on the same box as Exchange? And we do run Norton AV (I just hadn't mentioned it in my first post).
Thank you for your input on dual DC's...I still don't have the greatest understanding of the purpose, but I appreciate you letting me know one reason to have that setup.

 

[NickFerrar]

I've never tried running ISA on an Exchange server but I know ISA can be problematic enough without having to worry about it affecting the Exchange environment to. Are you using ISA to log web access? If so where will the SQL database sit for the logs to be written to? My experience is this is pretty resource intensive, I just wouldn't be comfortable doing it on a server already running Exchange.

Domain controllers authenticate users on a domain so if one isn't available people can't log onto the domain to use network resources (whether that's email, file, print or whatever). By having two it just means if one fails the other will service all the requests so people will authenticate as normal. Other situations you would have additional domain controllers is on a domain that is separated by a WAN link (say a 2Mb line) - you would have at least one DC at each site so the authentication traffic wouldn't go across the 2Mb line all the time (and to allow the people to authenticate even if the line fails).

As for restore times - typically it takes twice as long to restore as it does to backup. But if you don't need to restore all files at once it's not such a big deal. Spreading data out over multiple servers assumes only one server fails